Fathead minnows are opportunistic omnivores that can be characterized as benthic filter feeders, sifting through mud and silt in order to find food. Freshwater sediments often contain a large abundance of algae and protozoans, which represent a significant proportion of the fathead minnow diet. Secondary prey items include diatoms, filamentous algae, small crustaceans, and insect larvae. In addition, brook sticklebacks represent one of few species also common within the Prairie Pothole Region that also prey heavily on zooplankton, placing a high probability of interspecific competition between brook sticklebacks and fathead minnows. Differences in size-selection and feeding strategies, however, allow fathead minnows to consume a broader variety of zooplankton prey. Flexibility in feeding may explain why greater densities of fathead minnows exist in this region as compared to brook sticklebacks.
Animal Foods: insects; aquatic crustaceans; other marine invertebrates; zooplankton
Plant Foods: algae; phytoplankton
Other Foods: detritus
Foraging Behavior: filter-feeding
Primary Diet: carnivore (Eats non-insect arthropods); herbivore (Algivore); omnivore